Multi Inlet scrubber units, STI-TN-20170919-1

After some project experiences, Sox scrubber system from STI has been found to be effective in terms of installation space, weight, and power consumption. Our experience is to have one scrubber unit per each exhaust gas pipe; so called as “In-Line system with Single inlet”. This has been found to be useful when the installation takes place on existing ships as scrubber units can replace silencer units so that the amount of installation work and funnel casing modification work can be minimum.

The situation becomes a little different when comes to new building projects. Having a ‘large’ scrubber unit to accommodate exhaust gas flows from various diesel combustion units have some advantage over installing as many scrubber units as the number of diesel combustion units. Of course, there are some different considerations are to be made, like by-pass lines, isolation dampers, etc. This type of scrubbers are called as “In-Line system with Multi inlet”.

STI has modified its own scrubber design from “In-Line system with Single inlet” to “In-Line system with Multi inlet”. As a result, this is made as a new line of scrubber design together with the existing designs. As the scrubber units from STI are of “In-Line type” design, we call the new design as “Multi inlet system”.

Multi Inlet scrubber units are found to have some advantages of reducing the ‘overall volume’ of scrubber units installed onboard as the design is made by taking the operation modes into account. It, as a result, reduces overall installation weight as well as cost.

System sizing for multi inlet scrubber units are not very straight forward as there are many issues to be checked in advance. For example,

Number of diesel combustion units to be connected to the scrubber unit.

Considerations for the bypass lines by regulatory requirementsand/or maintenance point of view. (For the case of the scrubber system design from STI, bypass pipes are not necessary as it can be switches between “dry operation” and “(wet) operation” without making any changes.)

STI is pleased to include some design cases to help customers to have some ideas about scrubber unit size, weight, and utilities as below.